Loss of separation involving a Boeing 747, and McDonnell Douglas F/A-18A, 70 km east of Sydney, New South Wales, on 15 March 1993

Singapore Airlines Flight 288 [SIA288] was maintaining Flight Level [FL] 310 on a flight from Auckland to Singapore. It had been cleared to transit Restricted Area R588 at FL 310 by Sydney Sector 5 who had correctly co-ordinated the clearance with Williamtown Approach control.

Four RAAF FA18A aircraft, operating as Shogun Section, had completed an exercise to the south of R588 and requested a clearance from Williamtown Approach control to return to Williamtown for a landing. The controller cleared Shogun Section to transit R588 at FL 310 from south to north on a course that was in conflict with SIA288.

As the aircraft approached each other, Williamtown Approach noticed the confliction and passed traffic information to Shogun Section, who then initiated evasive action by climbing above the level of SIA288.

The crew of SIA288 was not given traffic information by Sydney control but saw two FA18A aircraft and assessed that their own aircraft would pass behind. They therefore elected not to take any other action.

The aircraft passed within 2.7 NM of each other with 900 ft vertical difference. The required separation standard is 5 NM or 2,000 ft and, as such, a breakdown in separation occurred.

Significant Factors

1. The RAAF controller issued clearances for SIA288 and Shogun Section without correct application of the appropriate separation standards.